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sLHC

sLHC. Summary WG4 ( BEAM DYNAMICS) A. Lombardi (CERN). “we are not too badly off but we have still a lot of work to do”. sLHC. Participants to the WG - CERN/BE/ABP : end-to-end multiparticle tracking; layout definition/validation; WG coordination.

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sLHC

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  1. sLHC Summary WG4 ( BEAM DYNAMICS) A. Lombardi (CERN) “we are not too badly off but we have still a lot of work to do” alessandra lombardi - SPL collaboration meeting - nov 09

  2. sLHC • Participants to the WG • -CERN/BE/ABP : end-to-end multiparticle tracking; layout definition/validation; WG coordination. • -CERN/TE/ABT : extraction areas; transfer lines ; collimation • -CERN/AB/RF : HOM calculations. • -ESS-S : end-to-end multiparticle tracking; layout definition/validation • - CEA Saclay : • -Soltan Institute : collimation • STFC/ Cockroft institute : collimation • TRIUMF : HOM calculations , WG coordination. alessandra lombardi - SPL collaboration meeting - nov 09

  3. sLHC alessandra lombardi - SPL collaboration meeting - nov 09

  4. sLHC HOM alessandra lombardi - SPL collaboration meeting - nov 09

  5. Agreed parameters for further simulations at June workshop • Other effects to be included as drivers of HOM are: • Variable chopping pattern and partially deflected bunches • Transverse alignment errors

  6. Conclusions of the June Wokshop • It was agreed that new simulations of the SPL case with the parameters shown in Table 2 should be performed before taking any conclusion on the need of HOM dampers. Heat dissipation because of HOMs shall also be evaluated. • The possibility to use a design similar to SNS, with the inter-cavity connections (bellows) providing sufficient HOM damping, shall be studied carefully. Should this not be sufficient in view of the results of the next simulations, a careful design (or possibly a test) of a sound technical solution for a damper shall be studied. Steps in this direction were presented during the discussion on “dampers technical solutions”. • It was also agreed that, because of the variety of potential future uses of the SPL, the superconducting cavities should be equipped with ports to allow both HOM monitoring as well as the possibility of adding dampers at a later stage. The design of these ports shall be part of the overall cavity design handled by the cavity working group.

  7. sLHC M Schuh – CERN/BE/RF Need to push current up a factor 10 to see a 10% effect . alessandra lombardi - SPL collaboration meeting - nov 09

  8. sLHC To be sure that with any chopping pattern beam dynamics will not be perturbed we need Q<105 alessandra lombardi - SPL collaboration meeting - nov 09

  9. sLHC alessandra lombardi - SPL collaboration meeting - nov 09

  10. sLHC alessandra lombardi - SPL collaboration meeting - nov 09

  11. sLHC Building blocks for Doublet Building blocks for FODO alessandra lombardi - SPL collaboration meeting - nov 09

  12. sLHC Compare Doublet vs FODO on 1) structure 2) beam dynamics 3) sensitivity to alignment 4) impact on cryo layout Structure : only difference is that the gradient of the quadrupoles is lower in FODO Beam dynamics : no real difference alessandra lombardi - SPL collaboration meeting - nov 09

  13. sLHC Sensitivity to alignment : slightly better for FODO Impact on cryo-layout : FODO is not compatible with warm magnets Decision : wait decision on cryo-segmentation before excluding one of the solution. alessandra lombardi - SPL collaboration meeting - nov 09

  14. sLHC alessandra lombardi - SPL collaboration meeting - nov 09

  15. sLHC D.Missaien : The alignment tolerances (0.3 mm) are not too challenging alessandra lombardi - SPL collaboration meeting - nov 09

  16. sLHC Correction system alessandra lombardi - SPL collaboration meeting - nov 09

  17. sLHC CONCLUSIONS : The quadrupolar signal in a Beam Pick up can be used to derive information about the beam envelope matching. Proof of principle placing the BPM inside a quadrupole on a test linac gives results comparable to having a standard profile meausrements. Details for SPL still to be worked out (position outside the quadrupole, reduction of acceptance) alessandra lombardi - SPL collaboration meeting - nov 09

  18. sLHC alessandra lombardi - SPL collaboration meeting - nov 09

  19. sLHC Drawing linac4 transfer line alessandra lombardi - SPL collaboration meeting - nov 09

  20. LINAC4 to SPL (160 MeV) sLHC CONCLUSIONS : A transfer line compatible with LINC4-to-PBS operation is defined Beam dynamics, also under effect of errors is satisfactory (small emitt increase and zero disper.) Space (2 X 1.8 meters are availiable and suitable (80 deg phase adv.) for collimation alessandra lombardi - SPL collaboration meeting - nov 09

  21. Extraction (1.5 and 2.5 GeV) sLHC CONCLUSIONS : At 1.5 GeV a solution fits, just skipping a cryomodule, no perturbation to periodicity of the lattice At 2.5 GeV we need to make more space (order 4-5 meters) and evaluate impact on dynamics. NB : WE HAVEN”T INTEGRATED THE DIAGNOSTICS YET alessandra lombardi - SPL collaboration meeting - nov 09

  22. SPL to PS2 (5 GeV) sLHC CONCLUSIONS : A transfer line layout has been established. Need to optimise transport with space charge and multiparticle simulations. Need to integrate RF to match the energy spread requirement and jitter at PS2 (tbd) Stripping : foil vs laser still to be studied in details Back-burner : effect and mitigation of blackbody radiation. alessandra lombardi - SPL collaboration meeting - nov 09

  23. sLHC • COLLIMATION : • Exploratory work going on at STFC and Soltan Institute • NEED COORDINATION : • Beam dynamics : beam halo and establish how much we want to collimate • Collimation optics : aperture and position • Collimation design : choice of material….. • RP consideration : shielding yes/no; how distant from a magnet ….. alessandra lombardi - SPL collaboration meeting - nov 09

  24. sLHC • Objective of this meeting : • Discuss and select ( or define what is needed to select) a focusing scheme/layout. [ok] • Validate alignment tolerances and correction system. [ok] • Define a path to finalize diagnostics requirement. [partly] • Solidify the collaboration with external institutes. […..…] • Define dates and topics of the next-year workshop(s) [ok] • Collimation . THANK YOU ALL for the interesting discussion and useful input alessandra lombardi - SPL collaboration meeting - nov 09

  25. sLHC alessandra lombardi - SPL collaboration meeting - nov 09

  26. sLHC alessandra lombardi - SPL collaboration meeting - nov 09

  27. sLHC Topics : Layout definition/validation, including connection from LINAC4, extraction at 1.4 GeV and 2.5 GeV, transfer lines Definition of tolerances (quads alignment and field quality, RF phase and amplitude) Definition of correction and monitoring system (steerers, diagnostics) HOM effects Compatibility with e- Impact of cavity performance: lower than nominal field (19MV/m low-beta 25MV/m high beta) , modules switched off…. alessandra lombardi - SPL collaboration meeting - nov 09

  28. sLHC • Priorities! • Study which have a strong impact on civil engineering : • Transition LINAC4-SPL (determine the position of the first cryo) • Layout including extraction areas • Study which have a impact cryo design : • Alternative focusing systems • Position of corrective elements • Position of cold diagnostics • Position of the warm diagnostics • Alignment studies • HOM dampers • The rest : • Collimation Loss control • Beam dynamics fine tuning • H- stripping in the transfer lines alessandra lombardi - SPL collaboration meeting - nov 09

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